Franca Sozzani, an influential figure on the international fashion scene who served as Editor-in-Chief of Vogue Italia for nearly three decades, died Thursday in Milan, according to the publication’s American counterpart. She was 66.

In the early 1980s, Sozzani, fresh from an assistant position at Vogue Bambini, landed a series of editorship positions, namely at Lei and Per Lui, where she was credited with nurturing the photographic talents of artists like Mario Testino, Paolo Roversi, Herb Ritts, Peter Lindbergh, Bruce Weber, and Steven Meisel.

Sozzani was appointed to the Editor-in-Chief position at Vogue Italia in 1988, a post she held for 28 years until her death. In the position, she evolved the magazine’s editorial content, producing photo spreads with high-profile models that touched on hot-button social and political issues like domestic violence and the 2010 BP Oil Spill. She was also the driving creative force behind the publication’s Black Issuein 2008, which highlighted models of color, including Naomi Campbell, Tyra Banks, Alek Wek, Iman, Jourdan Dunn, Chanel Iman, and former America’s Next Top Model contestant Toccara Jones.

She was also the subject of a documentary film directed by her son, Francesco Carrozzini, titled Franca: Chaos & Creation, currently traveling the festival circuit after screenings at the Venice Film Festival and AFI Fest.

After news of Sozzani’s death broke, various celebrities took to social media to mourn the fashion icon, including Vogue editor-in-chief Anna Wintour.

“Show by show and season by season, Franca and I found ourselves falling into a friendship that I am so happy and honored to say sustained itself for 30 years,” Wintour wrote in a post on the Vogue website. “That’s one thing that Franca taught me about friendship: Sometimes, you really have to earn it.”

She continued: “In private, Franca was warm, clever, funny, and someone who could give the Sphinx a run for its money when it comes to keeping a confidence. She was also the hardest-working person I have known, and with an envy-inducing ease with multitasking. She made everything she worked on appear effortless, regardless of whether it was an event for several hundred.”

Madonna also remembered Sozzani in an Instagram post on Thursday afternoon.

“R.I.P. Franca Sozzani!! A trail blazer and a True Rebel [heart]!” she wrote. “You are loved and adored by so many! We will miss you. Respect and admiration!!”

As he tweeted a photo of the late editor, Kanye West added: “Franca Sozzani was always so nice and sincere. You will be deeply missed.”

Read on to see what figures in the entertainment and fashion industries are saying about Sozzani’s death, below.